I am the owner of a vBulletin4 forum (classic) with about 30k of threads and 300k of posts.
After the rubbish that IB lately introduced (vBulletin5) I'd say that I will never upgrade! And because they have no reason to continue the development on vBulletin4 I would seriously look for alternatives.
Lets be honest! Both xenForo and IPB are better than vBulletin! They offer some great futures that vBulletin doesn't offer with great performance over vBulletin.
I started to test out IPB, it looks cool and funny and provides a wide range of add-ons and skins that beat xF's ones (even their default style is usable for a professional forum unlike xF's)! their pricing is a bit more expensive than xF (the basic fees) while the renewal fees are the double! Anyway, the pricing isn't an issue for me.
After that, I started to test out xF, the first thing I've noticed is the performance, in fact, it's incredibly fast! I liked the alerts function and how PMs are being displayed. something bad to mention about xF is it's skin structure. it's very basic and not professional, and the professional skins made by 3rd parties are quit few and can't be compared to those for IPB!
That was a small review and compensation between IPB and xF. Lets now go to the real subject
The real problem of the conversation (to xF or to IPB) is that about 92% from my visitors come from search engines! so, SEO is the most important side for me! especially that I got the first results with many good keywords which took me a very long time to get.
I've seen some reviews about converting vBs to IPB and most of the writers mentioned that they noticed a huge drop in their search engines traffic. that's why I came here to xenForo and not to IPB.
My question is, what is going to happen with my daily 30k+ of unique visitors?! and what will happen to my rankings with the good keywords mentioned above? I have a huge number of threads with PR4+ what will happen with them?
But please, before you reply, I don't need a "calm down xF SEO is good" replies! I would like to see real stories about conversations from vB to xF and it's impact on their traffic. it would be good if the stories are provided with traffic reports showing the month when the forum was converted.
BTW, I've used vBulletin without vBSEO and have the standard URLs (forumdisplay.php and showthread.php URLs)
A quick additional question: Does xF provide a converter from vBulletin 4.1.11 to the latest xenForo release?
I am so sorry for the very long thread, but I am really concerned about my forum's future after the conversation.
Thanks in advance to those members will reply with their stories (and even for who won't ) and I am also sorry for any English mistakes, I am not a native speaker